Onan Overspeed/Start Disconnect Module 0300-4324
This module is mounted on the bell cover, it reads the RPM of the generator shaft and will disconnect the starter at about 660 RPM and if the generator goes overspeed it will shutdown around 2190RPM (or for 50HZ operation 1830RPM).
We have reproduced these and they are for sale brand new. These aren't pulls or repairs they were built in 2017 by J.R. Electronics on brand new printed circuit boards. The OEM boards failed because of a part that deteriorates with age and heat so beware of buying a pull, it may be on it's last leg. We give one full year warranty on these boards.
We are also willing to repair your unit or to swap a new unit for an inop unit to speed your repair cycle. Call us.